Dr. Nikola Returns by Guy Boothby

When we left our rooms on this occasion we turned to the right hand instead of to the left, and proceeded to a long corridor running below that in which our cells were situated. Whereabouts in the monastery this particular passage was placed, and how its bearings lay with regard to the staircase by which we had ascended from the valley on the previous day, I could not discover. Like all the others, however, it was innocent of daylight, but was lighted by enormous torches, which again were upheld by iron brackets driven into the walls. Once during our march an opportunity was vouchsafed me of examining these walls for myself, when to my astonishment I discovered that they were not hewn out of the rock as I had supposed, but were built of dressed stone of a description, remarkably resembling granite. This being so, I realized, for the first time, that the cells and the corridors were built by human hands, but how long it could have taken the builders to complete such an enormous task was a calculation altogether beyond my powers. But to return to my narrative.

From the corridor just described we passed down another flight of steps, then across a narrow landing, after which came another staircase. As we reached it our ears were assailed by a noise resembling distant thunder.